Electrically propelled household devices



2, 1952 c. A. DOSTAL ETAL 3,056,152

ELECTRICALLY PROPELLED HOUSEHOLD DEVICES Original Filed July 22, 1955 [Mm/mp5 cum 4. DOSTAL FRAN DOST/4L rats The instant application is divided out of our application for patent, Serial Number 523,677, filed July 22, 1955, now Patent 2,950,772, issued August 30, 1960, and entitled Electrically Propelled Household Vacuum Cleaner.

The instant invention relates to devices, such as vacu- 11m cleaners, floor polishers, waxers, and the like, particularly of the kinds employed in the average household, which, while in the broad category of labor-saving devices, nevertheless still require appreciable physical effort on the part of the user in propelling them from place to place. The efifort so required is frequently enough to prevent the use of such devices by the physically handicapped, semi-invalids and convalescents.

It is an object of the invention to reduce to a minimum the physical, generally manual, effort required to operate various devices of the type which roll on, or travel over, the surfaces on which they act, for example, vacuum cleaners, carpet cleaners, floor waxers, floor polishers, scrubbers, scrapers, sanders, lawn mowers, etc., by making the devices self-propellent by a separate motor but more generally by the electric, or other, motor already incorporated in the device for actuating the work performing element or elements thereof.

Still another object of the invention is to provide household devices of such types which are propellable in the forward and in the backward direction selectively under the control of the user.

Still another object of the invention is to provide devices of the type above mentioned with a switching means to initiate and terminate the power propulsion.

Still another object is to provide such devices which can be propelled in both the forward and backward directions at the same speed or with one of such speeds, usually the forward speed, greater than the other.

Still a further object of the invention is to provide vacuum cleaner devices with driving means supplying substantial assistance in making turns.

Another object is to provide increased traction between the rotatable elements of the drive of such devices.

Still another object of the invention is to provide such a device in which the propelling drive assumes a neutral position when not in operation.

Still a further object is to reduce the amount of time spent by even normal persons in performing the tasks for which the device, for example, a vacuum cleaner or a floor waxer and polisher, is designed by incorporating in the device the power drive unit of our invention.

We accomplish the foregoing, and other, objects of the invention by providing a set of floor engaging rollers which is power driven by a system of driving rollers including at least one elastic belt and pulley between such set of rollers and a driving motor mounted on the device, or by any other system transmitting rotary motion, such as sprockets, chains, gearing, etc., driven by such motor. Where the motor is an electric motor, it is energized by providing a normally open switch in the handle of the device at the region Where it is usually held, which switch, on grasping the handle about the switch, is closed to connect the line supply to the motor. With the motor energized, when the handle is pulled, the power transaft ice

mission is so connected to the set of power driven floor engaging rollers that the device is propelled rearwardly, whereas when pushing on the handle, it is so connected thereto as to propel the device forwardly. The means for shifting the direction of power transmission includes a transversely aligned pair of levers to one end region of which the lower end of the device handle is pivotally connected, the pair of levers supporting one shaft of the power driving unit. This lever supported shaft, on which the power driven floor engaging rollers are mounted, may be displaced a limited amount from the true transverse direction of the device to enable making power turns by either making the levers of thin material so that they are flexible in torsion about their lengths or by mounting the shaft in flexible inserts in the levers. The main portion of the weight of the device is carried by these levers so that the rotatable elements of the drive which are longitudinally movable in the device tend to assume a neutral position in the unoperated position, since in the operating positions of the levers the other portions of the device are raised relative to the power driven floor engaging rollers.

Our instant invention will be more readily understood from the following detailed description of an illustrative embodiment thereof, in the form of a power drive for vacuum cleaners of the upright type, when read in conjunction with the appended drawing in which:

FIGURE 1 is a somewhat simplified elevational side view of a vacuum cleaner incorporating the driving unit of our invention, in which the parts of the vacuum cleaner not essential to the understanding thereof have been omitted, the floor engaging power driven rollers of which house both the forward and rearward driving rollers; and

FIGURE 2 is a top view of the driving unit of FIG- URE 1.

The vacuum cleaner incorporating an illustrative embodiment of our invention comprises essentially a formed housing 1, within which the motor 2, by way of a drive shaft 3, drives the brush 4 in the mouth of the suction tube of the cleaner, as also at least one fan in such suction tube which opens into a dust collector or bag. The fan on rotation creates suction at the mouth of the tube thereby drawing dust-laden air at such mouth into the tube and propelling it to the dust collector or bag, in well known manner. Since these latter elements are all well known in the art, only those essential to the disclosure and understanding of the instant invention are shown and referenced. The rear portion of the housing 1 is provided with a pair of transversely aligned rollers 5, 5, so supported therefrom that when the brush and these rollers are on the floor, the drive shaft 3 is in a predetermined position, for example, horizontal.

It is to be understood that the parts so far enumerated may be of any prior known type, and also that a primed reference character means that a like element is transversely opposite the non-primed element in the embodiment.

The self-propelling unit of the embodiment has a pair of frame members 6, 6 supported within the housing 1, each frame member being spaced from the lateral walls thereof and extending longitudinally therein. The brush 4 is fast on the brush shaft 7 which is rotatably supported at its end regions in the forward-portions of the frame members 6, 6, the brush side being designated the forward end of the device. The brush is driven by way of Y a pulley 8, integral with the midregion of the shaft 7, a

belt 9, and the motor shaft 3, the brush motion being in the clockwise direction as viewed in FIGURE 1 such that the tufts of the brush sweep forwardly on the floor at all times irrespective of the direction in which the device itself is moving. The ends of the brush shaft 7 extend transversely beyond the frame members and carry rollers 10, 1t) integral therewith, or are themselves formed as such rollers. At the rearward regions of the frame members 6, 6, the lower ends of the levers 11, 11 are pivoted at 12, 12', with the upper ends of such levers pivotally connected to the forked ends 13, 13' of the device handle 14 at 15, 15'. The forked ends 13, 13 extend through the device housing 1 by way of appropriate apertures.

An electric line switch 16, spring biased to its open position, is provided in the handle 14 at the upper region thereof, where it is normally grasped by the user; of which switch the blade, appropriately insulated, extends outwardly from the handle. When the user encircles the handle at that region with his hand, .the switch blade is depressed to close the circuit, connecting the line current by way of the usual plug to the motor 2.

The floor rollers 17, 17' of the power drive unit house both the forward drive rollers and the rearward drive rollers, the forward drive rollers being rotatable on an auxiliary shaft 18 supported in the frame members. The ends of the auxiliary shaft 18 extend through the frame members 6, 6 so as to position the forward drive rollers 19, 19' within the floor rollers 17, 17 while the drive rollers 1t), 10 are fixed on the respective ends of the brush shaft 7. To permit the insertion of the rollers 10, 10' and 19, 19' into the floor engaging rollers 17, 17 the latter are open on their faces adjacent respectively to the frame members 6, 6. As stated, the brush shaft is rotated from the motor shaft 3 by way of the belt 9 and the brush shaft pulley 8. The floor rollers 17, 17' are rotatably supported on the stub shafts 20, 20 of which the non-roller ends pass through the frame members 6, 6' by way of elongated apertures 21, 21', and are fixedly supported in the levers 11, 11 at a region thereof above the pivot pins 12, 12 in the frame members. The apertures 21, 21 are elongated to permit shifting of the stub shafts forwardly and rearwardly to a limited extent by the lever arms. The forward drive roller shaft 18 is fixed in the frame members at a distance from the brush shaft 7 so that at all times the roller 11) engages the roller 19, and the roller 10' engages the roller 19, to drive the rollers 19, 19' in the direction opposite to that of rollers 10, 10 respectively. The diameters of the drive rollers 19, 19 and 10, 10 are such that, coupled with the positioning vertically of the brush shaft 7 and the auxiliary shaft 18 below the stub shafts 20, 20, when one pair of the drive rollers, for example rollers 19, 19 engages the cylindrical interior surface of the floor rollers 17, 17, the other pair of drive rollers 10, 10" is disengaged from such surface. A pair of matched springs 22, 23 and 22', 23 each anchored at one end in the frame members 6, 6' and connected with their other ends to the region of levers 11, 11' above the apertures 21, 21, returns the levers to a neutral position when the handle 14 is released.

In operation, when the handle 14 is pushed forward, the levers 11, 11 force the stub shafts 2t), 20' forward towards the front end of the apertures 21, 21, thus moving the floor rollers 17, 17' forward to bring the inner cylindrical surfaces thereof into engagement with the forward driving rollers 19, 19 and driving the floor rollers counterclockwise and the vacuum cleaner forward. On the other hand, when handle 14 is pulled, the levers move the stub shafts rearward toward the rearward ends of the apertures and move the floor rollers rearward to engage their inner cylindrical surfaces with the rearward drive rollers 10, 10' which rotate the floor rollers clockwise and cause the vacuum cleaner to move in the rearward direction. Obviously, different forward and reverse speeds can be obtained by the use of an auxiliary roller on either the shaft 7 or shaft 18. Due to the mechanical advantage of the levers 11, 11', increased traction between the floor rollers and the drive rollers is obtained.

Power turns of the device are possible to either the right or left of the direction of device motion by suitably deflecting the handle 14 to the left or right, respectively. If now it is desired to negotiate a curve or turn with the vacuum cleaner, the handle 14 is pulled laterally in the direction opposite that of the desired turn, this being a normal and quite usual maneuver. Thus, as viewed in FIGURE 2, if the vacuum cleaner is to make a forward turn upwardly, the handle 14 at its grasped upper end at the switch 16 would be deflected downwardly while pushed forwardly. In so doing, the fork 13 would pull the lever 11 rearwardly about its pivot 12 causing the interior surface of the roller 17 to engage the roller 14 which, rotating clockwise, drives the roller 17 clockwise and rearwardly, whereas the fork 13' would push the lever 11' forwardly to cause the roller 19 to "engage the roller 10' and to drive the roller 17 counterclockwise and forwardly.

It is obvious that the particular speed at which the device, in which our power drive unit is incorporated, is propelled forwardly or rearwardly, is a matter of relative dimensioning of the various rotatable elements participating in the drive. For the belt shown in the embodiment a pulley, gearing, sprocket, and chain, etc., may readily be substituted. As above stated, the embodiment is provided with the equalized springs 22, 23 and 22, 23' for levers 11, 11' to assist in restoring the movable portion of the roller assembly to the neutral position in the absence of a push or pull on the handle. Furthermore, the embodiment, which actually discloses the drive and floor rollers bteween the frame member and the adjacent lateral wall of the device, may have them between the frame members. Also, the frame members may be the lateral Walls per se of the device. Obviously, also the positions of the drive rollers may be modified to have some or all of the drive rollers outside the floor rollers. The motor actuating the power drive unit of our invention may be a separate motor individual to such drive, rather than the motor already built into the device to actuate its other functions. Furthermore, the levers may be replaced by slide members supporting a shaft of the drive.

Various other changes will suggest themselves to the skilled worker in the art without departing from the teaching of the instant invention, for it is expressly to be noted and understood that the embodiment shown is not disclosed by way of limitation, and that our invention is as broad as the prior art permits and as defined in the appended claims.

What we claim is:

1. A household cleaner propelling unit comprising a plurality of cleaner supporting rotatable rollers, a pair of drive rollers longitudinally aligned with at least one cleaner supporting roller, means for selectively engaging either drive roller of the pair to the supporting roller and disengaging the other drive roller of the pair from such supporting roller, motor means on the cleaner for rotating one drive roller of the pair, the other drive roller of the pair being frictionally driven by the motor driven roller, and a handle extending from the cleaner connected to the means for selectively engaging the drive rollers of the pair to such supporting roller so that on pushing the handle that drive roller of the pair which will propel the cleaner forward engages the supporting roller and so that on pulling the handle that drive roller of the pair which will propel the cleaner rearward engages the supporting roller.

2. A household cleaner propelling unit comprising a plurality of cleaner supporting rollers, a pair of drive rollers aligned longitudinally with at least one of the supporting rollers, each drive roller being normally disengaged from the supporting roller, a fixed frame member, a handle connected to the frame member and extending from the cleaner, a lever pivoted at its lower end to the frame member connected at its upper end to the handle, and a stub-shaft on which the supporting roller is rotatably mounted, the stub-shaft being integral with an intermediate portion of the lever and extending through an elongated aperture defined by the frame member, a motor for rotating one drive roller of the pair, the other drive roller being driven by the motor driven roller of the pair, and a switch connected to the motor and supported in the handle such that on grasping the handle at the switch region the switch is connected to energize the motor, the handle on being pushed moving the stubshaft longitudinally in the elongated aperture to engage that drive roller of the pair for propelling the cleaner forward to the supporting roller while on being pulled moves the stub-shaft in the opposite direction longitudinally to engage the other drive roller of the pair propelling the cleaner rearward to the supporting roller.

3. A household cleaner propelling unit according to claim 2 in which a first shaft rotatably supported in the frame member integrally mounts one roller of the pair, a second shaft rotatably supported in the frame member is integral with the other roller of the pair, the supporting roller is cup-shaped, and both drive rollers are positioned within the cup portion of the supporting roller and engageable to different regions of the internal cylindrical face of the supporting roller.

4. A household cleaner propelling unit according to claim 3 in which the pair of drive rollers are in rolling contact with each other and the motor drives one of the first and second shafts.

5. A household cleaner propelling unit according to claim 2 in which a pair of tension springs is connected to opposite sides of the lever, each spring having one end anchored in the lever region above the stub shaft, and its other end in a region of the frame member below the elongated aperture, the pair of springs so positioning the drive rollers when the handle is neither pulled nor pushed and the switch is open that neither drive roller engages the supporting roller.

6. A propelling unit for household devices rollable on floors comprising a casing having side walls, a first shaft rotatably supported transverse of the device, a drive roller afiixed at each end of the first shaft, a motor for rotating the first shaft in a predetermined direction, a cup-shaped floor engaging roller at each side wall, a thin elongated lever twistable in torsion pivotally supported at the lower portion of each side wall, a stub-shaft extending from substantially the midregion of each lever about which the floor engaging roller is rotatable, each side wall defining an elongated aperture through which the stubshaft extends and is movable longitudinally of the device in either direction, a second shaft rotatably supported transverse of the device, a drive roller at each end of the second shaft and in rolling frictional engagement with the corresponding drive roller of the first shaft, each drive roller having at least a portion of the width of its cylindrical surface engageable to the inner cylindrical surface of the floor engaging rollers, a handle extending from the casing and having a forked end of which each fork is connected to the upper end region of a respective lever, and a switch in the handle electrically connected to the motor so that on energization of the motor and pushing the handle forward the drive rollers of one of the shafts are engaged to the floor engaging rollers to propel the device forward, on pulling the handle the drive rollers of the other shaft are engaged to the floor engaging rollers to propel the device rearward, and on deflecting the handle transversely one drive roller of the first shaft engages its cooperating fioor engaging roller while the drive roller oppositely positioned on the second shaft engages its floor engaging roller to propel the device in a turn opposite to the direction in which the handle is deflected transversely.

7. A propelling unit according to claim 6 for a cleaner in which a cylindrical brush is integral with the first shaft and the predetermined direction of the motor driven first shaft is counterclockwise, and in which the rollers of the first shaft are engageable to the floor engaging rollers to propel the cleaner forward.

8. A propelling unit according to claim 6 each drive roller is wholly within the cup portion of the floor engaging rollers, the cup portions of the transversely opposite floor engaging rollers face each other, and. each lever is biased by a pair of springs, one spring to each side of the lever, to a neutral position with each drive roller disengaged from the floor engaging rollers when the handle is unactuated and the motor deenergized.

References Cited in the file of this patent UNITED STATES PATENTS 

